Liquid-level gauge



April 1 2 1927.

A, NOVICK LIQUID LEVEL GAUGE Filed April 157, 1925 2 SheetshSheet 1 fllllllllllllllllll'lwillig!!! l Mai@ kd@ Aprll 12,192? A, NovlcK LIQUID LEVEL GAUGE //v VEA/ro@ n* @y Mm Paie-med Apr. 12,1927."

UNITED STATES P ,A

1,624,359` TENT oFF-ICE.l

ABBAHAIVL NOVICK, OF FLUSH-ING, NEW YORK, ASSIGNOR TO F. L. SMITHE MACHINE oo., INc., or NEW YORK, N. Y.,

A CRPQRATION F NEW YORK.

mourn-LEVEL GAUGE.

Application led April 17, 1925. Serial No. A23,796. Y

In my co-pending applications, Serial Nos. 13,164 and 13,165, filed March 5, 1925, I have described liquid level gauges of the type in which a submerged conduit is used,

l the pressure of air in which varies according to the liquid level. In such pendingapplicationI have also described and claimed a device for automatically introducing air into such conduit for the purpose of mainloftaining the conduit freewfrom liquid, and

thus at all times insuring accuracy of the' Ny present invention relates to improvements in said device 'for automatically introducing air into the conduit, the pressure 4of air in which is to be indicated. More particularly. my present invention relates to improving the efficiency of the device and to providing better sealing action between such device and the recording instrument.

Certain features disclosed, but not claimed herein, are claimed inA my pending applica- Ytion Serial No. 13,165, filed March 5, 1925,

entitled ,Liquid-level gauges.

My invention 'will bel best understood from the following detailed description taken with the annexed drawings in which:

Figure 1 is a. diagrammatic view partly in section illustra-ting one embodiment of the invention', while Figure 2 is a. similar view of a slightly modified form, and Figure 3 is a view of a modified form of pressure conduit terminal.

` Referring to the drawings by characters of reference, l10 denotes a tank, the liquid level in which it is desired to record while 1l is an vindicating instrument responsive to pressure, the form shown being a liquid manometer of the type ordinarily employed in gauges of the character. As shown, it comprises a reservoir or leg 12 communicating through a restricted passage 13 with a transparent tube 6 having a scale 17 which for convenience may be calibrated in gallons.

A conduit 18 transmits to indicating instrument 11 the pressure caused by -the height of liquid on the opening 19. thereof disposed immediately above the bottom of tank 10.y As shown, Aopening 19 may be vHared oi; expanded, whereby, as is well known in the art, variations in the height of liquid in conduit, caused by varying depths of liquid in the tank and by' escape of air'from the conduit dueto leaks and y other causes, are minimized.

A s in my above mentioned application, `Serial #13,165 I provide means for automatically 'introducing air in smallquantities into conduit 18 by utilizing variations in pressure occurring in an appropriate region of the internalcombustion engine used in connection with my improved gauge, as for example, the intake or exhaust manifold of the engine. As in thev preceding instance tmentioned, I provide means for utilizing this variation of pressure consisting of a casing in which is located diaphragm means movable in response to such pressure variation. This movement of the diaphragm is then caused by appropriate valves to act as a pump for introducing air intol the conduit 18.' I have'discovered, however, that better pumping efficiency will be had if'the region on the conduit side of' the diaphragm be made as small as possible, whereby it will have avery small minimum volume, or in other words if lthe so-called dead air space be a minimum.

In Fig. 1, I have shown one improved means of laccomplishing suoli result, while at the vsame time improving the pumping efficiency of the device. The means which I have shown consists of a diaphragm box 2 0 which is interiorly connected by means of a tube 21 which preferably terminates below the working level-of the liquid in reservoir 12 of the inanometer. Enelosing diaphragm box 20 is a casing' 210. the walls of which are spaced from box 20. Casing 21() is joined to intake or exhaust manifold 22 by means of vapipe or tube 23. Tube 2l is provided at a suitable point in its length with an air admission valve 24. Thus a sudden decrease in the pressure occurring in manifold 22 (as is of frequent occurrence in 9 the operation of an automobile) will cause the diaphragm box 20 to expand owing. to its spring action whereby air will be drawn in through valve 24. Then `noW thepressure in manifold'22 is increased, the dia-` l phragm box 20 is contracted, thereby forcing air through tube 21 into the reservoir 12, and thence into conduit 1S. By such construction, tlie minimum volume of the box may be made very small, d ue to the larger 1 surface acted upon by the external pressure.

Itis essential thatth-e air above the liquid level in reservoir 12 be effectively sealed against escape into the tube 2l as such an event would impair the accuracyY of the readl ing of the'glauge 11. I therefore bring the end of tube 21 beneath the working level or liquid in reservoir-12 as has been previously mentioned, whereby an effective seal is maintained against such escape of air; To further insure against such escape I have in the. arrangement shown in Fig. 1 provided a submerged non-return valve 25 A which acts to prevent the return of liquid in" reservoir 12. vThus by sealing tube 2l against the liquid, I achieve an excellent sealing "action against the air, particularly since it is easier to provide against the return of a liquid through the tube than it is ot air.

It Will thus be seen that I am able to pro vide such a seal by utilizing the liquid forming a part of thc gauge itselt', but it will be understood that a separate liquid seal'may be provided in case a gauge of a dii'erent type be used.

In F ig. 2 I have shown a. sliglitlymodified form in which the valve 25a is not submerged but is located without the reservoir 12. Should the liquid in reservoir 12*1 be forced intotube 2l, valve 25 will function .to stop its ow. In the arrangement Fig.

2 I have also made use of the principle 4of having a minimum dead air space between the diaphragm and the pressure conduit, as shown a single diaphragm 20a is used, being held within a casing 210*l which is only very slightly spaced from diaphragm 20a particularly on the side of tube 21B.

In Fig. 3 I have shown the pressure conduit 180 terminating in a horizontally extending position 181. .This has the advan tage that a 'reserve supply of air is provided to insure'a-gainst absorption and leakage when lthe automobile is not running, as liquid may fill the entire portion 181 before an error is introduced which will affect the gauge. Thus after the automobile has stood over night, for example, the gauge will give a true reading when starting.

It will thus be seen that I have provided a device of high eliciency for automatically supplying air to the pressure responsive conduit of a gauge of the character described, and that furthermore I have made use ot a. liquid seal for preventing the return of the air from .the conduit making use of a non-return valve which shall be actuated by liquid rather than b v air. whereby a more positive sealing action is had.

It will be understood that the arrangeunts shown are illustrative only and thus many changes may be made in the construc` tion without departing Ifrom the spirit ot mv invention or thcscope of theclaims.

IVhat I claim is:

1. In a device .t'or indicating the depth of li uid in a tank. a conduit extending into tie tank and having au opening communicating with the liquid therein so as to nccted to said conduit.

be subjected to the head of liquid on said opening, indicating means connected to be responsive to the pressure in the Yconduit. means for automatically introducing air into said conduit, comprising anoperative connection between a source of air under pressure and said conduit, a, noureturn valve in said connection, and ini-ans constituting a chamber containing liquid in which said` non-return valve is submerged.

2. In a device for indicating the dept-h of liquid in a tank. a conduit extending into the tank and having an openingcommunieating with the liquid therein so as to be subject to the head of liquid on said openingpa manometer connected for indicating pressure in said conduit,V means for automatically introducing air into said conduitcomprising a` tube connecting a source of' air under pressure an'd said conduit, sa-id tube terminating beneathl the working,r level of liquid in said manometer, and a valve submerged in said liquid for preventing the return of air from the manometer to the tube.

3. The device for use in connection with an internal combustion engine as described in claim 1 in which the automatic means for introducing air into the conduit com- `prises a pumping member, and means `for actuating said member by the changes in pressure in a manifold of the engine.

4. The device for use in connection with an internal combustion engine as described in claim 2, in which automatic means for introducingair into the conduit comprises a pumping member, and means for actuating said member by the changes in pressure in a manifold of the engine.

5. The device for useI in connection with an internal combustion engine as described in claim 2, in which the automatic means for introducing air into the conduit comprises a diaphragm box and means for actuating said diaphragm box by the changes in pressure in a manifold of the engine, said diaphragm Vnox being of comparatively small minimum volume whereby changes in vol-.

unie ot said box wil-l produce comparatively large increments of air added to said conduit.

G. The device for use in connection with an internal combustion engine as described in claim 2, in which the automatic means tor introducing air into the conduit comprises a diaphragm box and means for actuating said diaphragm box by the changes in pressure in a manifold of the engine, the interior ot the diai nag-m box being con 7. In a, device tor indicating the depth of liquid `in a` tank, a conduit extending into the tank and having an openingr communi eating with the liquidtherein so as tc be subject to the head oi liquid on said opening, a source of variable pressure, indicating means connected to be responsive to the pressure in the conduit, and lneans for automatically introducing air into said conduit, comprising a deformable closed box in communication with the conduit, and a casing suriounding the deformable box, and having a chamber communicating with the source of variable pressure.-

8. In a device for indicating the depth of liquid in a tank, a conduit extending into the tank, and having an opening communicating with the liquid therein so as to be subject to the head of liquid on said opening, indicating means connected to be responsive to the pressure in the conduit, and means for automatically introducing air into said conduit', comprising a pressure chamber, and a deformable box'lioused in the pressure chamber and communicating with the conduit, said chamber being subject to variations in pressure.

i). In a device for indicating the depth ot' liquid in a tank, a 'conduit extending into the tank and having an opening communicating with the liquid therein so as to be-subject to the head of liquid on said opening, manometer indicating means comprising a gauge liquid, said means being connected to be responsive to the pressure in the conduit, means orintroducing air into said conduit, comprising a tube extending into the gauge liquid'whereby the air is caused to be introduced into the conduit through the gauge liquid, and a non-return valve in said tube below the level 'of the gauge liquid. j

10. In a device for indicating the'depth ot' liquid in a tank, a conduit extending into the tank and having an opening communicating with the liquid therein so as to be subject to the head of liquid on said opening, a source of variable pressure, indicating means connected to be responsive to the presl sure in the conduit, and means for automatically introducing air into said conduit comprising a thin, Wafer-like box in communication with the conduit, the sides of said box vbeing formed of thin, metallic plates ,cdas to render the box deformable i'nrespouse to variations inpressure,and a casing surrounding the said box, and means connecting the interior of said casing with the source'of variable pressure.

. In testimony whereof I have atiixed my signature to this specification.

ABRAHAM N OVICK. 

